ML20205K182

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Informs of Modifications That Util Made to CO(2) Fire Suppression Sys,Due to Sen 188 Which Occurred at Ineel on 980728.Compensatory Actions Will Remain in Place Until Modifications Are Complete & Systems Are Returned to Svc
ML20205K182
Person / Time
Site: Vermont Yankee Entergy icon.png
Issue date: 03/31/1999
From: Balduzzi M
VERMONT YANKEE NUCLEAR POWER CORP.
To:
NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
BVY-99-44, NUDOCS 9904130013
Download: ML20205K182 (2)


Text

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, VERMONc YANKEE NUCLEAR POWER CORPORATION

- Ferry Road. Brattleboro. VT 05301-7002 V

(802) 257-5271 March 31,1999 BVY 99-44 U.S. Nuclear Regulatory Commission ATTN: Document Control Center Washington, D.C. 20555

Reference:

(a) Letter, VYNPC to USNRC," Fire Systems Out of Service Greater Than 14 Days" BVY 98-168, dated December 17,1998

Subject:

Vermont Yankee Nuclear Power Station License No. DPR-28 (Docket No. 50-271)

CO Fire Suppression System Modifications 3

On October 2,1998 the Institute of Nuclear Power Operations (INPO) issued Significant Event Notification (SEN) 188. This SEN detailed an unexpected CO 2fire suppression system discharge at the Idaho National Engineering and Environmental Laboratory (INEEL) on July 28, 1998.

This event at INEEL resulted in multiple injuries and one fatality when the CO 2 system discharged without any warning alarm.

During the review of this SEN it was determined that there is a remote possibility that Vermont Yankee could have an event in which an unexpected CO2 discharge could happen without any warning alarm. Based on the seriousness of an unexpected activation of a CO2 fire suppression system to plant employees, the Cable Vault, East Switchgear Room, and West Switchgear Room CO2 system automatic discharge capability was removed from service. Compensatory actions were established in accordance with Vermont Yankee Technical Specifications.

Modifications are currently underway to install mechanical delay timers and CO2 Powered sirens in series with the current electrical timers and bells. This modification will ensure that even with I p' i a complete fire alarm panel failure a pre-discharge warning alarm will activate allowing I employees to safely exit these areas. 1 l

i Vermont Yankee indicated to the NRC in Reference (a) that the CO2 fire suppression systems l would be returned to service by March 31,1999. At the time of that letter the entire scope of the )

modification was not completely known. Extensive research was performed both in the nuclear 7 j

and general industry to determine the best balance between fire safety and personnel safety. This y ;

letter is submitted to provide an update on the modification and to indicate that a completion and [ f I return to service date early in May 1999 is anticipated. Compensatory actions will remam in \ l place until the modifications are complete and the respective systems are returned to service. l 9904130013 990331 PDR ADOCK 05000271 S PDR  ;

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VERMONT YANKEE NUCLEAR POWER CORPOR ATION BVY 99-44 Page 2 of 2 We trust you will find this submittal satisfactory. However, should you desire additic .al information, please feel free to contact us.

Sincerely, VERMONT YANKEE NUCLEAR POWER CORPORATION h  !

Michael A. Balduzzi Plant Manager

(

cc: USNRC Region 1 Administrator USNRC Resident Inspector-VYNPS USNRC Project Manager-VYNPS Vermont Department of Public Service I

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